JP2008030172A - Grinding machine and grinding method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a grinding machine capable of improving grinding accuracy by correcting and grinding a projecting part, even if the projecting part is formed on a surface to be machined of a workpiece when grinding the workpiece. <P>SOLUTION: The flatness of the surface 15a to be machined of the workpiece 15 is measured and detected by a flatness detecting sensor 24 after finishing the grinding of the surface 15a by a rotary grinding wheel 22. A regrinding position and a grinding amount are calculated based on a detection result by the flatness detecting sensor 24. In this case, contour line processing is performed for the surface 15a, and the regrinding position and the grinding amount are calculated so that a contour line of a prescribed height or higher may be extinguished. Correction grinding is executed to improve the flatness according to the arithmetic result. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a grinder that grinds a work surface of a workpiece with a rotating grindstone, and more particularly to a grinder that performs correction grinding of a work surface.

  In the conventional grinding machine, for example, as shown in FIG. 4, the rotating grindstone 22 is brought into contact with the work surface 15 a on the work 15 and the work 15 is extended with respect to the rotating grindstone 22. The work surface 15a of the workpiece 15 is ground by relative movement in the direction. At this time, when the workpiece 15 is large, as shown in FIGS. 4 and 5, a plurality of reinforcing ribs 15 b are often formed on the back surface of the workpiece 15. In this way, when the work surface 15a of the large workpiece 15 is ground, the portion not corresponding to the reinforcing rib 15b of the work surface 15a is compared with the portion corresponding to the reinforcing rib 15b, as shown by the chain line in FIG. And since rigidity is low, the amount of bending accompanying the contact pressure of the rotating grindstone 22 becomes large. As a result, as shown in FIG. 5 and FIG. 6, the actual grinding amount is smaller in the portion not corresponding to the reinforcing rib 15 b of the processing surface 15 a than in the portion corresponding to the reinforcing rib 15 b, There is a problem in that a plurality of convex portions 25 are formed on the surface 15a and the grinding accuracy is lowered.

  On the other hand, a table for mounting a workpiece is supported so as to be movable on the frame, and a pair of machining heads equipped with tools for machining from both sides of the workpiece are mounted on the frames on both sides of the table. In a machine tool supported so as to be movable in a direction perpendicular to the head, a configuration has been conventionally proposed in which precise positioning of the moving position of the table and the moving position of the machining head is performed (see, for example, Patent Document 1). ).

In this conventional configuration, the frame has a substantially cross-shaped main frame portion formed integrally with a table support portion for supporting the table and a pair of head support portions for supporting each processing head, and the main frame portion. It is comprised from a pair of extension frame part connected with the both ends of this table support part. According to this configuration, it is possible to easily perform precise alignment between the movement position of the table and the movement position of the machining head on the main frame portion integrally formed with the table support portion and the pair of head support portions. . For this reason, the tool of each processing head can be made to respond | correspond correctly to the predetermined processing position of the workpiece | work on a table, and a highly accurate process can be given to the both sides | surfaces of a workpiece | work.
JP 2002-59326 A

  However, according to the conventional configuration described in Patent Document 1, since the movement position of the table and the machining head can be precisely aligned, the machining accuracy of the workpiece can be improved. For this reason, in such a conventional technique, it is also conceivable to execute precision machining by applying this conventional technique by changing a machining tool or the like. However, even if the accuracy of the table, machining head, etc. is improved, it is difficult to suppress the degradation of machining accuracy during workpiece grinding because the workpiece machining accuracy decline is caused by deformation of the workpiece. .

  The present invention has been made paying attention to such problems existing in the prior art. The purpose is to improve the grinding accuracy by correcting and grinding the convex part due to workpiece deformation on the workpiece surface when grinding a large workpiece. An object of the present invention is to provide a grinding machine that can perform the above.

  In order to achieve the above object, the present invention provides a detecting means for detecting the flatness of a work surface ground by a rotating grindstone, and a regrind position and a grinding amount according to a detection result by the detecting means. And a control means for executing correction grinding so as to improve the flatness in accordance with the calculation result of the calculation means.

  Therefore, in this grinding machine, the flatness of the work surface is detected by the detecting means after the work surface of the work is ground by the rotating grindstone. Then, the regrind position and the grinding amount are calculated based on the detection result, and the correction grinding is executed so as to improve the flatness according to the calculation result. Therefore, even when a convex part is generated on the workpiece surface during grinding of a large workpiece, the convex part and the bulge part can be corrected and ground easily and accurately, thereby improving the grinding accuracy. Can do. Moreover, it is sufficient to grind only the convex portion, and correction can be performed in a short time. Here, the convex portion indicates a protruding portion such as a bulging portion.

  Further, in the above configuration, the calculation means may be configured to perform contour line processing on the surface to be processed and calculate a regrind position and a grinding amount so that a contour line of a predetermined height or more disappears. When configured in this way, the regrind position and grinding amount can be calculated appropriately based on the contour processing of the work surface, and correction grinding of the work surface can be performed more easily and in a short time. It can be carried out.

  Furthermore, in the above-described configuration, the calculation means may be configured to calculate a regrind position for each contour line when there are a plurality of contour lines. In the case of such a configuration, it is possible to perform correction grinding of the work surface separately for each contour line.

  Further, in the above configuration, the calculation means may be configured to compare a prescribed grinding amount and flatness, calculate an actual grinding amount, and determine a corrected grinding amount according to the calculation result. . When configured in this way, the actual grinding amount can be calculated in advance, the correction grinding amount can be determined according to the calculation result, and the number of times of repeated correction grinding of the work surface can be reduced. it can.

  As described above, according to the present invention, even when a convex portion or a swollen portion is generated on the workpiece surface during grinding of a large workpiece, the convex portion or the like can be corrected and ground. Processing accuracy can be improved.

(First embodiment)
Below, 1st Embodiment of this invention is described based on FIGS.
As shown in FIG. 1, in the grinding machine of this embodiment, a table 12 is disposed on a bed 11 via a rail 13 so as to be movable in the X axis direction in a horizontal plane, and is moved by an X axis direction moving motor 14. Then, it is moved in the X-axis direction via a ball screw or the like (not shown).

  A large work 15 is placed on the table 12, and as shown in FIGS. 4 and 5, a work surface 15a is formed on the upper surface, and a plurality of reinforcing ribs 15b are formed on the back surface. Has been.

  As shown in FIG. 1, a column 16 is disposed on the bed 11 via a rail 17 so as to be movable in the Y-axis direction orthogonal to the X-axis direction in a horizontal plane, and is moved by a Y-axis direction moving motor 18. Then, it is moved in the Y-axis direction via a ball screw or the like (not shown). A machining head 19 is supported on the front surface of the column 16 via a rail 20 so as to be movable in the Z-axis direction perpendicular to the X-axis direction in a vertical plane. Is moved in the same Z-axis direction.

  As shown in FIG. 1, a rotating grindstone 22 is supported on the machining head 19 so as to be rotatable on an axis extending in the Y-axis direction, and is rotated by a grindstone rotating motor 23. Then, by the movement of the column 16 in the Y-axis direction, the rotating grindstone 22 is arranged corresponding to a predetermined grinding position of the work surface 15a on the workpiece 15. In this state, the rotating grindstone 22 is rotated and brought into contact with the workpiece surface 15a of the workpiece 15 by the downward movement of the machining head 19 in the Z-axis direction. At the same time, the work 15 is moved relative to the rotating grindstone 22 by the movement of the table 12 in the X-axis direction, and the work surface 15a of the work 15 is ground.

  As shown in FIG. 1, a flatness detection sensor 24 constituting detection means is supported on the side surface of the machining head 19 so as to be movable between an upper retracted position and a lower detected position. 1, the flatness detection sensor 24 is moved from the retracted position to the detection position after the grinding of the work surface 15a of the work 15, and the detection sensor is moved downward by the machining head 19. The 24 detection units 24 a are brought into contact with the work surface 15 a of the workpiece 15. In this state, the workpiece 15 is moved relative to the flatness detection sensor 24 by the movement of the table 12 in the X-axis direction and the movement of the column 16 in the Y-axis direction, and the detection sensor 24 moves the workpiece 15a. Flatness is detected.

Next, the circuit configuration of the grinding machine configured as described above will be described.
As shown in FIG. 2, the CPU 31 outputs a drive signal to each of the motors 14, 18, 21, 23 according to a program stored in the ROM 32, or inputs a detection signal from the flatness detection sensor 24, Controls the overall operation of the grinding machine. The RAM 33 stores various data generated in accordance with the execution of the program. The input unit 34 includes a keyboard or the like, and inputs data such as the size and material of the workpiece 15 and the amount of grinding of the work surface 15a by the rotating grindstone 22. The display unit 35 includes a display or the like and displays data input from the input unit 34.

  Then, the CPU 31 constitutes a calculation means, and when a signal for detecting the flatness of the work surface 15a is inputted from the flatness detection sensor 24 after the grinding of the work surface 15a of the work 15 by the rotating grindstone 22, the detection is performed. According to the result, the regrind position and the grinding amount on the work surface 15a are calculated. In this case, as shown in FIG. 7 and FIG. 8, the contour line 25a, 25b, 25c having a predetermined height or more disappears by contouring the convex portion 25 that needs to be reground on the work surface 15a. Re-grinding position and grinding amount are calculated. When there are a plurality of contour lines 25a, 25b, and 25c, the regrind positions for the contour lines 25a, 25b, and 25c are calculated. Further, the CPU 31 constitutes a control means, and executes correction grinding with the rotating grindstone 22 so as to improve the flatness according to the calculation result. The flatness detection sensor 24 is moved up and down by an actuator such as a motor (not shown). And at the time of the process by the rotary grindstone 22, it arrange | positions in a raise position so that the workpiece | work 15 may not be contacted.

Next, the operation of the grinding machine configured as described above will be described.
In this grinding machine, when the workpiece surface 15a of the large workpiece 15 is ground by the rotating grindstone 22, a plurality of reinforcing ribs 15b are projected from the back surface of the workpiece 15, and the reinforcing ribs 15b of the workpiece surface 15a are projected. Since the rigidity is lower in the portion not corresponding to the portion corresponding to the reinforcing rib 15b, the amount of deflection accompanying the contact pressure of the rotating grindstone 22 becomes larger as indicated by the chain line in FIG. For this reason, as shown in FIGS. 5 and 6, the actual grinding amount is smaller in the portion not corresponding to the reinforcing rib 15b of the processed surface 15a than in the portion corresponding to the reinforcing rib 15b. A plurality of convex portions 25 are formed on the processing surface 15a, and re-grinding for correcting these convex portions 25 is required.

  Therefore, in this grinding machine, after grinding the work surface 15a of the workpiece 15 by the rotating grindstone 22, the operation of each step (hereinafter simply referred to as S) of the flowchart shown in FIG. That is, in S1, it is determined whether or not the grinding process of the workpiece 15 has been completed, and when the grinding process is completed, the process proceeds to S2. In S <b> 2, the flatness detection sensor 24 is lowered to the detection position, the machining head 19 is moved downward, and the detection unit 24 a of the detection sensor 24 is brought into contact with the work surface 15 a of the workpiece 15. In the next S3, the workpiece 15 is moved relative to the flatness detection sensor 24 by the movement of the table 12 in the X-axis direction and the movement of the column 16 in the Y-axis direction. The flatness of 15a is measured, the measured detection signal is output to the CPU 31, and the flatness data, that is, the vertical position data of the processing surface 15a is stored in the RAM 33. In S4, the flatness detection sensor 24 is raised to the retracted position, and the machining head 19 is moved upward to the upper position.

  After that, in S5, the CPU 31 compares the detection result of the flatness detection sensor 24 with the specified flatness stored in the RAM 33 in advance, and whether there are irregularities that exceed the specified value on the work surface 15a of the workpiece 15. It is determined whether or not. And when there is no unevenness | corrugation more than a regulation value on the to-be-processed surface 15a, a correction grinding operation is complete | finished as what the to-be-processed surface 15a is ground by the regular flatness. On the other hand, as shown in FIGS. 5 and 6, if there is an unevenness of a predetermined value or more such as the protrusion 25 on the processing surface 15a, the process proceeds to the next S6.

  Subsequently, in S6, as shown in FIGS. 7 and 8, the contour line 25a, 25b, and 25c are set by performing contour line processing on the convex portion 25 that needs to be reground on the processing surface 15a. In the next S7, the rotating grindstone 22 is moved and arranged at a regrind start position corresponding to one convex portion 25 on the work surface 15a. Thereafter, in S8, the grinding range and the number of times of grinding by the rotating grindstone 22 are calculated such that one contour line 25a to 25c in one convex portion 25 disappears. And in S9, according to the calculation result of S8, the grinding of the to-be-processed surface 15a is performed by the rotating grindstone 22.

  In the next S10, the flatness detection sensor 24 performs re-measurement of the surface 15a to be corrected and the contour line processing, and it is determined whether or not the uncorrected ground contour lines 25a to 25c remain. The When the contour lines 25a to 25c remain, the process returns to S8, and the operations of S8 to S10 are repeated. When the contour lines 25a to 25c do not remain, the process proceeds to S11. In S11, it is determined whether or not the correction grinding has been completed for all the convex portions 25 on the processing surface 15a. When the correction grinding of all the convex portions 25 is completed, the process returns to S2 and the subsequent operations are repeated to detect the flatness of the work surface 15a and corrective grinding of the convex portions 25 again. Is called.

  On the other hand, if the correction grinding of all the convex portions 25 is not completed in the determination of S11, the process proceeds to S12. In S12, the rotating grindstone 22 is moved to the regrind start position corresponding to the next convex portion 25 on the work surface 15a. Thereafter, the process returns to S8, and the subsequent operations are repeatedly performed. For the convex portion 25, the grinding range and the number of times of grinding are calculated for each of the contour lines 25a to 25c, and correction grinding is performed according to the calculation result.

  In addition, the said convex part 25 arises according to the wave | undulation of the workpiece | work 15, a planar shape, etc. besides the reinforcement rib 15b. Further, when the rotating grindstone 22 rotates at a high speed, frictional heat is released from the portion of the reinforcing rib 15b via the reinforcing rib 15b, but the other portion expands due to accumulation of frictional heat. Grinding is performed. For this reason, the amount of grinding of the portion other than the reinforcing rib 15b increases, and a convex portion may be formed in the portion of the reinforcing rib 15b due to cooling shrinkage after the completion of grinding.

As described above, the grinder of this embodiment that is operated has the following effects.
(1) After grinding the work surface 15a of the work 15 by the rotating grindstone 22, the flatness of the work surface 15a is measured by the flatness detection sensor 24, and the regrind position and the grinding amount are calculated based on the measurement result. At the same time, correction grinding is performed so as to improve the flatness according to the calculation result. Therefore, even when the convex portion 25 occurs on the work surface 15a of the workpiece 15, the convex portion 25 can be corrected and ground easily and accurately, and the grinding accuracy can be improved. In addition, since the entire workpiece 15 is not subjected to correction grinding, only the portion of the convex portion 25 is subjected to correction grinding. Therefore, the correction grinding can be performed efficiently and in a short time, and particularly useful for a large workpiece 15. It is.

  (2) In this grinding machine, when the re-grinding position and the grinding amount are calculated, the contour line processing is performed on the work surface 15a, and the re-grinding position and the grinding so that the contour lines 25a to 25c having a predetermined height or more disappear. A quantity is calculated. At this time, when there are a plurality of contour lines 25a to 25c, the regrind position is calculated for each of the contour lines 25a to 25c. Therefore, the regrind position and the grinding amount on the work surface 15a can be calculated appropriately, and the correction grinding of the work surface 15a is performed for each of the contour lines 25a to 25c more easily and in a short time. Can do.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with a focus on differences from the first embodiment.
In the second embodiment, the operations of S8a to S8d as shown in FIG. 9 are performed instead of the operation of S8 in the blow chart of FIG. 3 in the first embodiment. That is, in S8a, the height of the convex portion 25 on the processing surface 15a measured by the flatness detection sensor 24 is compared with a predetermined grinding amount set in advance, and the actual grinding amount by the previous grinding process is compared. Is calculated. For example, when the prescribed grinding amount is 1 μm but the convex portion 25 with a height of 0.5 μm remains, it is assumed that only 0.5 μm of grinding has actually been performed. 0.5 μm (50%) of the grinding amount is calculated.

  In the next S8b, the corrected grinding amount for one contour line 25a to 25c is calculated based on the calculation result of S8a. For example, when the calculated actual grinding amount is 0.5 μm (50%), when the convex portion 25 having a height of 0.5 μm is corrected and ground with a normal prescribed grinding amount of 0.5 μm, the height is set to 0. The convex part 25 of 25 micrometers will remain again. Therefore, in S8b, the corrected grinding amount is calculated by adding the actual grinding amount of 0.5 μm (50%) calculated in S8a to the ratio in advance. Then, according to this calculation result, the grinding range is calculated in S8c, and the number of times of grinding is calculated in S8d.

  Therefore, also in the second embodiment, the same effects as those described in the first embodiment can be obtained. In the second embodiment, the following effects can be obtained.

  (3) The actual grinding amount is calculated by comparing the prescribed grinding amount with the detected flatness, and the corrected grinding amount is determined so that the prescribed grinding is performed according to the calculation result. For this reason, the correction grinding amount actually executed can be set according to the calculated actual grinding amount, and the number of times of repeated correction grinding of the work surface 15a can be reduced.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
In the said embodiment, although illustrated about the case where the to-be-processed surface 15a on the workpiece | work 15 which formed the reinforcement rib 15b on the back surface was protruded, it implements when grinding the to-be-processed surface of another workpiece | work. .

  -Instead of the rotating grindstone 22 as a grinding tool, embody a grinding machine using another tool such as a milling cutter or a cup grindstone.

The partially broken front view which shows the grinding machine of 1st Embodiment. The block diagram which shows the circuit structure of the grinding machine of FIG. The flowchart which shows the correction grinding operation | movement of the grinding machine. The front view which shows the state which grinds a workpiece | work with a rotating grindstone. The top view which shows the state of the workpiece | work after grinding. The front view which similarly shows the state of the workpiece | work after grinding. The partial expanded front view explaining the contour line process for the correction grinding of a workpiece | work. The partial top view explaining the contour-line process of a workpiece | work similarly. The flowchart which shows a part of correction grinding operation | movement of the grinding machine of 2nd Embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Bed, 12 ... Table, 14 ... X-axis direction moving motor, 15 ... Workpiece, 15a ... Work surface, 15b ... Reinforcement rib, 16 ... Column, 18 ... Y-axis direction moving motor, 19 ... Processing head, DESCRIPTION OF SYMBOLS 21 ... Motor for Z-axis direction movement, 22 ... Rotary grindstone, 23 ... Grinding wheel rotation motor, 24 ... Flatness detection sensor, 25 ... Convex part, 25a ... Contour line, 25b ... Contour line, 25c ... Contour line, 31 ... Calculation means and CPU constituting control means.

Claims (5)

Detection means for detecting the flatness of the work surface ground by the rotating grindstone;
According to the detection result by the detection means, calculation means for calculating the regrind position and the grinding amount;
A grinding machine comprising: control means for executing correction grinding so that flatness is improved in accordance with a calculation result by the calculation means. 2. The grinding machine according to claim 1, wherein the calculation unit performs contour line processing on the surface to be processed, and calculates a regrind position and a grinding amount so that a contour line of a predetermined height or more disappears. The grinding machine according to claim 2, wherein the computing means calculates a regrind position for each contour line when there are a plurality of contour lines. The said calculating means compares the prescribed grinding amount and flatness, calculates the actual grinding amount, and determines the corrected grinding amount according to the calculation result. The grinding machine as described in any one of. Detects the flatness of the work surface ground by the rotating grindstone,
According to the detection result, calculate the regrind position and grinding amount,
A grinding method characterized by performing correction grinding so that flatness is improved according to the calculation result.

Images